Today Is June 6th…D-Day; The Largest Amphibious Invasion In History

The Normandy Landings were the first operations of the Allied invasion of Normandy, also known as Operation Neptune and Operation Overlord, during World War II. The landings commenced on June 6, 1944 (D-Day), beginning at 6:30 British Double Summer Time (H-Hour). In planning, D-Day was the term used for the day of actual landing, which was dependent on final approval.

The assault was conducted in two phases: an air assault landing of American, British and Canadian airborne troops shortly after midnight, and an amphibious landing of Allied infantry and armoured divisions on the coast of France commencing at 6:30. The invasion required the transport of soldiers and materiel from the United Kingdom by troop carrying aircraft and ships, the assault landings, air support, naval interdiction of the English Channel and naval fire-support.

There were also subsidiary ‘attacks’ mounted under the codenames Operation Glimmer and Operation Taxable to distract the Kriegsmarine and the German army from the real landing areas. The operation was the largest single-day amphibious invasion of all time, with 160,000 troops landing on June 6, 1944. 195,700 Allied naval and merchant navy personnel in over 5,000 ships were involved. The landings took place along a 50-mile (80 km) stretch of the Normandy coast divided into five sectors: Utah, Omaha, Gold, Juno and Sword. The Allies had previously invaded mainland Europe September 3, 1943 with the landings in Italy.

The Allied invasion was detailed in several overlapping operational plans according to the D-Day museum:

“The armed forces use codenames to refer to the planning and execution of specific military operations. Operation Overlord was the codename for the Allied invasion of northwest Europe. The assault phase of Operation Overlord was known as Operation Neptune. Operation Neptune began on D-Day ( June 6, 1944) and ended on June 30,1944. By this time, the Allies had established a firm foothold in Normandy. Operation Overlord also began on D-Day, and continued until Allied forces crossed the River Seine on 19 August.”

Only a few days in each month were suitable for launching the operation, because both a full moon and a spring tide were required: the former to illuminate navigational landmarks for the crews of aircraft, gliders and landing craft, and the latter to provide the deepest possible water to help safe navigation over defensive obstacles placed by the Germans in the surf on the seaward approaches to the beaches.

Allied Expeditionary Force Supreme Commander Dwight D. Eisenhower had tentatively selected 5 June as the date for the assault. Most of May had fine weather, but this deteriorated in early June. On 4 June, conditions were clearly unsuitable for a landing; wind and high seas would make it impossible to launch landing craft, and low clouds would prevent aircraft finding their targets. The Allied troop convoys already at sea were forced to take shelter in bays and inlets on the south coast of Britain for the night.

It seemed possible that everything would have to be cancelled and the troops returned to their camps (a vast undertaking because the enormous movement of follow-up formations was already proceeding). The next full moon period would be nearly a month away. At a vital meeting on 5 June, Eisenhower’s chief meteorologist (Group Captain J.M. Stagg) forecast a brief improvement for 6 June. General Bernard Montgomery and Eisenhower’s Chief of Staff General Walter Bedell Smith wished to proceed with the invasion. Leigh Mallory was doubtful, but Admiral Bertram Ramsay believed that conditions would be marginally favorable. On the strength of Stagg’s forecast, Eisenhower ordered the invasion to proceed.

The Germans meanwhile took comfort from the existing poor conditions, which were worse over Northern France than over the Channel itself, and believed no invasion would be possible for several days. Some troops stood down, and many senior officers were away for the weekend. General Erwin Rommel, for example, took a few days’ leave to celebrate his wife’s birthday, while dozens of division, regimental, and battalion commanders were away from their posts at war games.

The order of battle for the landings was approximately as follows, east to west:

British Second Army

6th Airborne Division was delivered by parachute and glider to the east of the River Orne to protect the left flank. The division contained 7,900 men, including one Canadian battalion.

3 responses to “Today Is June 6th…D-Day; The Largest Amphibious Invasion In History”

So very pleased to see this article and those incredibly brave men remembered.
My father died March 17 2008, Lt.Col.J.A.Clancy,M.B.E. M.C. C.D.-Canadian Battalion, who joined up with the 6th British Airborne Division and I had the fortune of listening to him before he died at almost 90 years of age, recount the landing east of the river Orne.He was in charge of his platoon and there are never enough words to express the mens’ bravery and indomitable courage.Lt.Col.John A.Clancy , my father,how fortunate we are to have had them.Thank you for the clips.
They do not make them like him anymore.God Bless all the men and all, rest in peace.We love you.